Coolant discharge system for grinding machine

ABSTRACT

Coolant is directed into the machining zone during a grinding operation through a primary coolant discharge which substantially floods the entire machining zone with coolant, under pressure, and a secondary discharge which directs coolant specifically to critical heat points on the grinding wheel and workpiece. Coolant, under pressure, is contained in the machining zone by a container placed in front of both the grinding wheel and workpiece. The container substantially conforms to the configuration of the periphery of the workpiece, and channels coolant, under pressure, around the periphery of the workpiece keeping the machining zone and workpiece substantially flooded with coolant during grinding operations.

O United States Patent 1 [111 3,712,001 Kaeserneyer et al. [4 1 Jan. 23,1973 1 COOLANT DISCHARGE SYSTEM FOR 2,788,622 4/1957 Weber ..5l/267 xGRINDING MACHINE 2,228,386 l/l94l Burns ..5l/267 M l,l85,l82 5 1916 D..51 267 [75] Inventors: Carl W. Kaesemeyer, Cincinnati, I am I ohfo; MCmcmnau" Primary Examiner-Donald G. Kelly Ohm Attorney-Howard T. Keiserand Jack 1. Earl 73 A .M,i,,,..-..... ..W U 1 sslgnee glklllicgmfllacron Inc., Cincinnati, [57] ABSTRACT [22] Filed, 5, E "Coolant isdirected into the machining zone during a-igrinding operation through aprimary coolant- U PP N06 112,949 discharge which substantially floodsthe entire machining zone with coolant, under pressure, and a secondarydischarge which directs coolant specifically 52 US. Cl. E 5 In. CL 1 tocritical heat points on the grinding wheel and work- I 58] Field 215 HMpiece. Coolant, under pressure, is contained in the' 1/216 ,i, 216machining zone by a container placed in front of both the grinding wheeland workpiece. The container sub- 56 stantially conforms to theconfiguration of the l 1 References cued periphery of the workpiece, andchannels coolant, UNITED STATES PATENTS under pressure, around theperiphery of the workpiece keeping the machining zone and workpiecesubstan- 3 1 :l tially flooded with coolant during grinding operations.

I OSC 3,l28,580 4/ 1964 Davis ..5l/267 X 6 Claims, 8 Drawing Figures1,963,448 6/1934 Robbins ..5l/356 3,548,549 7/1968 Dunn ..5l/267 .X

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COOLANT DISCHARGE SYSTEM FOR GRINDING MACHINE BACKGROUND OF'THEINVENTION The present invention relates to coolant and guard systems forgrinding machines and more particularly to coolant systems utilized withhigh speed, high efficiency grinding.

In high speed grinding, the workpiece and the grinding wheel rotaterelative to each other at a rate often exceeding 12,000 surface feet perminute. This creates an air flow around the workpiece and forms a highpressure area directly above the operating zone which is difficult topenetrate with coolant. The coolant which is directed toward theworkpiece and more specifically toward the grinding zone is picked up bythe air flow and directed away from the point of contact between thewheel and workpiece, instead of toward it. Due to lack of sufficientcooling a temperature in excess of the acceptable operating temperatureresults often damaging the workpiece and causing excessive wheel wear. Asecondary result is violent splashing of coolant into the environmentaround the machine.

In the past, several attempts have been made to contain the coolant anddirect it to the critical operating zone with varying degrees ofeffectiveness. One prior art attempt was to place an air deflector abovethe coolant nozzle and adjacent to the wheel thus reducing the air flowdirectly above the operating zone. While this is satisfactory forconventional grinding techniques, it is not satisfactory when utilizedwith high speed, high efficiency grinding. The air flow around thegrinding wheel is too great and the coolant must be released at highpressure to break the residuary air flow. Another prior art attempt wasto force the coolant into the porous grinding wheel at a pointcalculated to cause a release of the coolant through centrifugal forceat the point of grind. This also has proved to be unsatisfactory. Thecoolant carries small metal chips with it and the wheel acts as a filterto remove the chips. This causes clogging of the pores of the grindingwheel creating a safety hazard, reducing coolant flow, causingworkpieces to heat excessively, and increasing wheel wear.

The present invention satisfactorily contains the coolant and directs ittoward the surface of the workpiece. It further satisfactorily providesa means for directing the coolant to a critical area of the workpiece.The invention further provides a means for loading and unloadingworkpieces without requiring the operator to manually place theworkpiece between centers in a center-type grinding operation.

The present invention is particularly contemplated for use with theguard system of the type shown and described in the co-pending patentapplication of Howard W. Renner and John A. Moores for Guard System forHigh-Speed Grinder, Ser. No. 68,114, filed Aug. 3l, 1970 and assigned tothe assignee of the present invention. In this cited application ahollow shield is placed above the workpiece and adjacent to the grindingwheel to protect the operator from any fragments of an explodinggrinding wheel during a grinding operation. Coolant flows through thisshield for cooling the workpiece and the grinding wheel. This coolantalso serves as an energy absorber in the event that a fragment from anexploding grinding wheel strikes and pierces the hollow shield.

The coolant system of the present invention additionally provides ameans for containing the coolant in the machining zone and directing thecoolant, under pressure, toward the point of contact between the wheeland workpiece. The coolant system also provides a method for directingcoolant onto critical heat areas where excess coolant is needed tomaintain the workpiece and wheel at an acceptable operating temperature.The present invention further provides satisfactory means forautomatically loading and unloading workpieces between centers in acenter-type operation.

It is an object of the present invention to provide a means fordirecting coolant into the machining zone and eliminating violentsplashing of coolant into the environment around the machine withoutadversely effecting the safe operation of the grinding machine.

Another object of the present invention is to direct coolant in varyingamounts to the critical heat areas of the workpiece and grinding wheel.

It is further an object of this invention to provide a convenient meansfor loading and unloading workpieces.

Other features and objects of the present invention will be readilyperceived from the following description, claims and drawings.

DESCRIPTION OF THE DRAWINGS The attached drawings illustrate thepreferred embodiments of the invention, in which:

FIG. 1 is a sectional view of a grinding machine wheelhead and tableutilizing the preferred embodiment of the present invention.

FIG. 2 is a view, partially in elevation and partially in section,showing the rear portion of the preferred embodiment.

FIG. 3 is a view similar to FIG. 1 with the wheel-head and the hollowshield moved away from the machining zone for loading and unloading ofworkpieces.

FIG. 4 is a perspective view of the coolant container.

FIG. 5 is an enlarged fragmentary view of FIG. 1 showing the coolantflow during a machining operation.

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 5.

FIG. 7 is a view similar to FIG. 1 showing means for automaticallyloading and unloading parts utilizing the present invention.

FIG. 8 is a sectional view along lines 8--8 of FIG. 7.

DESCRIPTION: STRUCTURAL MODE Referring to the drawings in detail, andmore particularly to FIG. 1 thereof, there is shown in section a portionof a grinding machine having a support base 10 on which is slidablysupported a wheel head 11. A grinding spindle 12 is rotatably supportedby the wheelhead 11 and has a grinding wheel 13 fixed to one endthereof. The other end of the spindle 12 is connected in the well-knownmanner to a drive motor (not shown) for rotating the grinding wheel 13.

The wheelhead 11 has a grinding wheel guard 14 supported thereon forcooperating with the grinding wheel 13 in the mannermore particularlyshown and described in the aforesaid Renner et al. application. Thegrinding wheel guard 14 has a deformable liner 15 made of a rigid closedcell composition to absorb some of the energy from fragments of thegrinding wheel 13 in the event of the wheel bursting.

The base has spaced rear walls 17 and 18 (see FIG. 2) extending upwardlytherefrom to form a space 18 therebetween into which the grinding wheel13 extends. The rear wall 17 has a side wall 19 secured thereto bysuitable meanssuch as welding, for example, and extending forwardlytherefrom. Similarly, the rear wall 18 has a side wall 20, substantiallyparallel to the side wall 19, connected thereto and extending forwardlytherefrom. The rear wall 17 and side wall 19, and the rear wall 18 andside wall are secured to support base 10 in the manner more particularlydescribed in the aforesaid Renner et al application.

A top plate 21 is secured to the tops of the side walls 19 and 20 and tothe top of the rear wall 17 and 18 by a suitable means such as machinescrews (not shown). As shown in FIGS. 1 and 3, the plate 21 extends overthe top of guard 14.

The workpiece 22 is supported between a headstock 23 and a footstock 24in the well-known manner. The workpiece 22 is rotatably driven bydriving means 51 during grinding thereof.

A primary door or shield 26 has an upper end extending through a slot 27and top plate 21 and is connected to a piston rod 28 of a hydrauliccylinder 29. This cylinder is pivotally mounted on a bracket 30, whichis fixed to the top plate 21. A hollow pin 31 is welded to primary door26 and ends of the hollow pin 31 pivot in blocks 72 and 73 which aresecured to plate 21. The shield 26 is formed ofa thick front plate 32and sheet metal means 33, which is comprised of a plurality of membersforming the top wall and side walls of the shield 26. The sheet metalmeans 33 cooperates with the plate 32 to form a chamber 34 therebetween.A coolant fluid is introduced into the chamber 34 through a longitudinalslot 34' in the lower portion of the hollow pin 31.

When the piston rod 28 has been retracted into the cylinder 29, theshield 26 is held in the position shown in FIG. 1 where the front plate32 of the shield abuts against the rails or blocks 35 and 36, which aresupported by the side walls 19 and 20, respectively. In this position,the coolant flows from the chamber 34 through a nozzle 37 at the lowerend of the'shield 26 onto the grinding wheel adjacent to the workpiece22.

According, the shield 26 prevents, in the event of the wheel bursting,any fragments of the grinding wheel 13 from escaping between theworkiece 22 and the top plate 21 since the lower end of the shield 26 isdisposed adjacent the top of the workpiece 22. The coolant which isflowing through the chamber 34 and the shield 26, additionally serves asan energy absorber for fragments of the grinding wheel 13, should itexplode and collapse sheet metal means 33.

The coolant is directed under pressure into the machining zone 40through a suitable primary discharge means, for example, the nozzle 37which consists of an aperture 41 and deflectors 38 and 42 are attachedto plate 32 by a suitable means such as welding. The deflector 38directs coolant into the wheel 13 at a point directly above theworkpiece 22. The deflector 42 deflects coolant bouncing off theworkpiece and the wheel back into the operating zone 40. Adjacent thedeflector 42, and of substantially the same configuration as theperiphery of the workpiece 22is a container 43 which holds the coolant,under pressure, in the machining zone 40. As seen in FIG. 5, thecoolant, therefore, substantially surrounds the workpiece 22; keepingthe workpiece 22 in contact with the coolant for a longer period of timethan conventional systems and minimizing the heat retained by theworkpiece 22 and wheel 13 during a grinding operation.

The preferred embodiment of the container 43 is depicted in FIG. 4. Itis basically a C-shaped deflector, the upper edge 44 abutting thedeflector 42 and the lower edge 45 conforming generally to the shape ofthe wheel face 46 of the grinding wheel 13. The end wall 47 of thecontainer 43 is substantially closed but has an opening 48 therein forentry of center 49 of the footstock 24 that holds the workpiece 22during grinding. The opposite end of the container 43 is open for accessto the driving means 51 of the headstock 23. The container 43 hassecured to it a bracket 52 which is suited for fastening the container43 to the base 10 of the grind ing machine as shown, for example, inFIG. 1.

Placed in the hollow chamber 34 is a secondary discharge means, forexample the hollow tube 53. The tube 53 has one end 54 open and placedin the longitudinal slot 34 of the hollow pin 31 in the manner shown inFIG. 2. The tube 53 is made ofa rigid material such as steel, forexample, and extends through the side portion of the sheetmetal means 33and extends to the bottom of the shield 26.

The container 43 can be utilized in an automatic loading sequence as thecarrier for both unfinished and finished workpieces. An example of thecontainer utilized in this manner is illustrated in FIGS. 7 and 8. Fourcontainers 43a-d are rigidly connected together in ferris wheel fashionby the spokes 56 which are complimentary to each other. The hub 57 issecured to the rotatable pin 58 which rotates each instance, beingdriven in the well-known manner. Above the upper most container 43a andadjacent to it is a transfer means 59 for transferring an unfinishedworkpiece 22 into the container 43a which in turn carries the workpiece22 into the machining zone for grinding thereupon.

The container 43b is in the identical position as the container 43 in amanual loading-type operation. Thus it serves as a-coolant container andcarries'workpiece 22 into, and out of, the machining zone. 2

Base 10 of the grinding machine is then cut away to follow the path ofrotation 61 of the carrier 430 as it releases a finished workpiece 22.At the point 63 where the workpiece 22 is released from the container430 the contour 62 continues downward to remove the finished workpiece22 to a receptacle means (not shown).

DESCRIPTION: OPERATION MODE Manual Loading Before the initial grindingbegins, the wheel 13, guard structure 14, and shield 26 are in theposition shown in FIG. 3. The workpiece 22 is then placed in thecontainer 43 manually by the operator. The footstock center 49 and thedriving means 51-which includes a center (not shown) for locating theworkpiece 22 then secure the workpiece 22 in the operating position. Thedriving means 51 then rotates the workpiece. The

cylinder 29 is next actuated retracting the rod 28 and bringing shield26 into the working position as shown in FIG. 1. Coolant then begins toflow through the hollow pin 31 and the longitudinal slot 34 into thechamber 34 and into the open end 54 of the tube 53. Coolant flowsthrough the nozzle 37 and into the machining zone 40.

As shown in FIG. 6, the first workpiece 22, ofa series of likeworkpieces, is secured in the machining zone. A portion of the sealedend 55 of the hollow tube 53 is ground away by the initial approach ofthe wheel, thus allowing coolant to escape through the opening and ontoa critical heat point of the workpiece, for example the shoulder portionof the workpiece 22.

Also, on this initial approach the wheel 13 grinds away a portion of thedeflector 38 of the nozzle and the edge of the container 43. Thisprocess insures a close fit between the face of the wheel 46 and theedge 45 of the container 43, the deflector 38, and the end of the tube53. Thus, coolant is directed to and container in the critical regionsof the workpiece 22 during a grinding operation.

On successive workpieces of the same size and configuration as theworkpiece 22, the tube 53 and the edge 45 do not have to be furtheraltered.

The coolant flows substantially as shown in FIG. 5, completelysurrounding the workpiece 22 during grinding. The coolant also flows outof the end 55 of the tube 53 and into a critical heat point on theworkpiece 22, such as the shoulder of the workpiece 22 as illustrated inFIG. 6.

The wheel 13 continues to feed into finish size. When the workpiece 22is to size, the wheel 13 and guard system 14 then retract. After thewheel 13 is retracted the cylinder 29 is actuated, extending the rod 28,thus retracting the shield 26 to the position shown in FIG. 3.

The footstock 49 then releases the workpiece 22. The operator can removethe finished workpiece 22 and replace it with a new, unfinishedworkpiece. The cycle is then repeated.

automatic Loading In an operation using automatic loading techniques thegrinding wheel 13 again grinds away a portion of the tube end 55 and thedeflector 38. However, the edge 45 of the container 43 is ground away onthe first pass of each of the containers 43a-d, and a completerevolution of the loading device 64 is necessary before all containers43a-d are sized to fit the contours of the wheel face 46.

workpieces 22 are stored in a bin 65 in the manner well-known.Initially, one workpiece 22 drops into the transfer tube 66 as shown bythe workpiece in phantom in FIG. 8. The push rod 67 then pushes theworkpiece 22 into the stop 68. The push rod 67 then retracts into thecylinder 69 (as shown in phantom in FIG. 8) and a second workpiece 22drops into the transfer tube 66. When the empty container 43a reachesthe position shown in FIG. 7, the stop 68 retracts into the cylinder 70and the push rod 67 pushes the workpiece 22 (in phantom) which in turnpushes the forward workpiece 22 into the container 43a. As soon as thehead 71 of the forward workpiece 22 is past the stop 68, the stop 68 isextended to halt the progress of the rear workpiece 22 6 as it movesinto position. At this point the loading mechanism 64 is as illustratedin FIG. 8 and the push rod 67 then retracts to the phantom position andthe cycle is ready to repeat.

The loaded container 43a then rotates to the position of container 43b,the footstock center 49 and the center of the headstock 23 locate andsecure the workpiece 22. Next, headstock drive 5] begins to rotate theworkpiece 22. The piston 28 is then retracted into cylinder 29, closingthe shield 26, and the grinding wheel l3'begins infeed. While grindingis being performed the new empty container 43d is loaded in the mannerherein described. After grinding is complete the wheel 13 and the guardstructure 14 retract. The piston 28 is then extended from the cylinder29 removing the shield 26 from the machining zone40. The headstock drive51 then stops and the footstock center 49 releases the workpiece 22. Theloading mechanism 64 then rotates bringing a new workpiece 22 into themachining zone 40 and the grinding operation is ready to recycle.

As the loading mechanism 64 rotates the container 43b follows the path61 to point 63 where the finished workpiece 22 rolls out of container43b and as the mechanism 64 continues to rotate the finished workpiece22 rolls down path 62 into a suitable receptacle (not shown).

For purposes of exemplification, particular embodiments of the inventionhave been shown and described according to the best presentunderstanding thereof. However, it will be apparent that changes andmodifications in the arrangement and construction of the parts thereofmay be resorted to without departing from the spirit and scope of theinvention.

What is claimed is:

I. In a grinding machine having a grinding wheel and a workpiece, adriving means for rotating said workpiece, and a securing means tolocate the workpiece in the machining zone, an improved pressurizedcoolant system for cooling the workpiece and grinding wheel duringgrinding, comprising:

a. primary means discharging coolant under pressure in the regionadjacent the machining zone; and

b. a container directing coolant around the periphery of the workpieceand containing the coolant in the machining zone, substantially floodingthe machining zone in coolant under pressure.

2. The apparatus of claim 1 wherein said primary means comprises:

a. an aperture through which coolant is discharged under pressure;

b. a guide which directs coolant, under pressure, into the wheeladjacent to the point where the wheel contacts the workpiece; and

c. a deflector which deflects coolant spray, bouncing off the wheel andthe workpiece, back into the machining zone.

3. The apparatus of claim 2 wherein said container has an edge nearestsaid primary discharge means which overlaps the deflector of saidprimary discharge means.

4. The apparatus of claim 1 wherein said container comprises:

a. a thin walled, rigid structure which substantially conforms to theshape of the periphery of the workpiece;

b. an edge on one side of the machining zone which fits adjacent theprimary discharge means for reducing leakage between said primarydischarge means and said container;

c. another edge on the other side of the machining zone which fitsadjacent the wheel and conforms substantially to the configuration ofthe face of said wheel;

d. an open end which permits access of the workpiece driving and supportmeans to said work- 1 a. an arm of rigid material which is fixedlysecured to the container and extending therefrom; and r b. a pin whichis rotatably secured to rigid structure of the grinding machine and towhich said arm is fixedly secured, whereby said container is moved intoand out of the machining zone by rotating said pin.

6. The apparatus of claim I wherein there is introduced a secondarydischarge means discharging coolant under pressure at critical heatareas of the workpiece comprising a hollow tube of rigid constructionwherein:

a. coolant under pressure is introduced into one open end of said hollowtube; and

b. the other open end of said tube is positioned adjacent a criticalarea of the workpiece for discharging coolant under pressure thereon.

1. In a grinding machine having a grinding wheel and a workpiece, adriving means for rotating said workpiece, and a securing means tolocate the workpiece in the machining zone, an improved pressurizedcoolant system for cooling the workpiece and grinding wheel duringgrinding, comprising: a. primary means discharging coolant underpressure in the region adjacent the machining zone; and b. a containerdirecting coolant around the periphery of the workpiece and containingthe coolant in the machining zone, substantiaLly flooding the machiningzone in coolant under pressure.
 2. The apparatus of claim 1 wherein saidprimary means comprises: a. an aperture through which coolant isdischarged under pressure; b. a guide which directs coolant, underpressure, into the wheel adjacent to the point where the wheel contactsthe workpiece; and c. a deflector which deflects coolant spray, bouncingoff the wheel and the workpiece, back into the machining zone.
 3. Theapparatus of claim 2 wherein said container has an edge nearest saidprimary discharge means which overlaps the deflector of said primarydischarge means.
 4. The apparatus of claim 1 wherein said containercomprises: a. a thin walled, rigid structure which substantiallyconforms to the shape of the periphery of the workpiece; b. an edge onone side of the machining zone which fits adjacent the primary dischargemeans for reducing leakage between said primary discharge means and saidcontainer; c. another edge on the other side of the machining zone whichfits adjacent the wheel and conforms substantially to the configurationof the face of said wheel; d. an open end which permits access of theworkpiece driving and support means to said workpiece; e. a closed endwherein there is an aperture for permitting access of the workpiecesupport means to said workpiece; and f. a support means which supportsand secures the container to rigid structure of the grinding machine. 5.The apparatus of claim 4 wherein said container support means comprises:a. an arm of rigid material which is fixedly secured to the containerand extending therefrom; and b. a pin which is rotatably secured torigid structure of the grinding machine and to which said arm is fixedlysecured, whereby said container is moved into and out of the machiningzone by rotating said pin.
 6. The apparatus of claim 1 wherein there isintroduced a secondary discharge means discharging coolant underpressure at critical heat areas of the workpiece comprising a hollowtube of rigid construction wherein: a. coolant under pressure isintroduced into one open end of said hollow tube; and b. the other openend of said tube is positioned adjacent a critical area of the workpiecefor discharging coolant under pressure thereon.